Hull FC ran out 35-18 winners on Friday to leapfrog neighbours Hull KR in the table and pile the pressure on struggling Salford City Reds.
The Reds dominated the second half of the match at The Willows but paid for a dismal 23-minute spell in which they conceded four tries.
They also leaked two more tries in the last two minutes of the match to go down to their seventh defeat of the season and remain just a point above bottom club Huddersfield Giants.
Their misery was compounded by another injury to skipper Malcolm Alker, who made his comeback from torn knee medial ligaments 21 minutes into the game but was forced off again 12 minutes later.
Salford were never out of the top six last season but they will sink to the foot of the table if the Giants beat Wigan Warriors on Sunday yet they made the best possible start with two tries in the first six minutes.
Smart passing by Luke Robinson and Ian Sibbit created a two-on-one for centre Aaron Moule to exploit after just four minutes and Hull had barely recovered from the shock when a blunder by full-back Shaun Briscoe gifted the Reds a second try.
Briscoe waited for Robinson